I played against a discard lock today and he was out of cards on turn 10 and I still had 22 cards left in my deck, because of Prince Malchezaar. My opponent had 7 health left and some minions on the board. 1 of them was Tiny Knight of Evil.

Goddamnit. This one could have been a 1-drop. 1-drops have very limited design space and this effect can be tacked onto a 1-drop easily. Why make it the same cost as Succubus? To dent the synergy further? Discard warlock is just clunky.